This invention concerns the brazing together of two materials, for example, a ceramic and a metal, having different coefficients of thermal expansion. U.S. Pat. No. 4,690,876 discloses the use of a ductile brazing alloy foil for that purpose. However, such a ductile brazing alloy foil is generally satisfactory only for relatively small parts, say, less than about one inch in cross section at the jointure area. Column 1, lines 5-16 of U.S. Pat. No. 4,598,025 discloses the use of a molybdenum copper composite interlayer between two such parts to be brazed. U.S. Pat. No. 4,562,121 discloses the use of a cushion layer, for example, copper, between two solder layers between the two parts to be joined.